Blade grading machine



Nov. 4-, 1941. s, BURNS 2,2a1,75s

BLADE GRADING MACHINE Filed May 23, 1940 5 ShSQtS ShSBt 1 FIQI. 6766 6 9 i HVENTOR 3'0 HN STEPHENJURNS' Nov. 4, 1941. J. 5. BURNS 1 2,261,753

BLADE GRADING MACHINE Filed May 23, 1940 v 5 Sheets-Sheet 2 65 a7 8889 EH3 CID INVENTGR r JOHN STEPHEN aumus NOV. 4, 1941. RN 2,261,753

BLADE GRADING MACHINE Filed May 25, 1940 5 Sheet-Sheet 5 I NW4, 1941'. S BURNS 2,261,753

BLADE GRADING MACHINE Filed May 23, 1940 I 5 Sheets-Sheet 4 INVEN-raR Uol-m sTEPHEN BURNS Nov. 4, 1941. J. s. BURNS BLADE GRADING MACHINE Tiled May 25, 1940 5 Sheets-Sheet 5 INVENTOR .Johrv 5. But-8N5 sv Li QHQRNEY Patented Nov. 4-, 1941 2,261,753 v BLADE GRADING- MACHINE John Stephen Burns, rWalton-on-Thames, England Application May 23, 194:0, Serial No. 336,800 In Great Britain April 5, 1939 '13 Claims. (Cl. 37156) This invention relates to blade grading machines, with more especial reference to road graders, patrols and maintainers used principally for making earth or gravel roads in which a blade is adjustably mounted on a steerable vehicle so as to be capable of cutting the earth and imparting the desired profile to the surface traversed or passed by the machine.

In my prior Patent No. 2,074,081 a construction of grading machine is described, including a longitudinally extending main frame mounted on wheels, a member transversely encircling the main frame and mounted thereon for rotation about a longitudinal and substantially horizontal axis, the said member carrying a plough frame with mouldboard and blade and means being provided for rotating it, for moving it up and down in an approximately vertical plane and for moving it laterally in regard to the main frame, thus to position the blade as regards depth of cut and sideshift.

In this prior construction the encircling member was formed as an annulus or ring embracing a control structure or subframe movable vertically and laterally in relation to the main frame through the medium of screwthreaded stems, and to enable final cambering adjustments in the position of the blade to be effected by actuation of thestems, independently in the same or opposite direction, resort was had to arcuate guides for slidably mounting the subframe or structure on the stems.

The present invention has reference to grading machines of this general character and has for its object to provide an improved construction enabling final adjustment and cambering of the blade to be effected if need be while the machine is at work, without th necessity for a slidable connection between the screwthreaded stems and the subframe.

Further and favorable objects will appear from the following description.

In accordance with the present invention the screwthreaded vertical stems are universally mounted at or near the extremities of the transverse guide members which are laterally adjustable in relation to the main frame, .and the stems are anchored in relation to the subframe or control structure in turn carrying the annular member mounting the plough circle, the universal mountings for the stems riding a slide or guide- Way provided for the purpose on the subframe or control structure. thus to relieve the screwthreaded stems of bending moment.

In the .case :of patrols ,and maintainers, the

iii

. each way, afforded by the screwed stems ismore than sufificient for these machines and indeed is adequate for all purposes other than steep sidesloping or battering.

In either event this subframe is preferably rectangular so that the plough frame or circle is conveniently mounted directly thereon for the patrol or maintainer or Where the annular member is interposed to provide for the circular movement of the blade, this is readily and freely carried by rollers borne adjacent the corners of the rectangular subframe.

Advantageously, in addition to the normal unidirectional movement of the stems to modify the depth of cut, provision is made for actuating the stems independently or in opposite directions, thus finely to adjust the angleor camber ofthe blade and to this end the universal mountings for the screwthreaded stems at each end of the transverse members are trunnioned therein, one

or both of the trunnions affording relative movement betweenthe mounting .and the transverse members to .the degree necessary to aocommoe date the angular setting of the structureto the requisite extent, e. g., about 25,on each side of thehorizontal.

The gearboxes for actuating the screwthreaded stems may be positioned at the extremities of the aforementioned transverse members, and may, constitutethe universal mounting in which case the screwthreaded stems are so anchored to the subframe or control structure as to be 5 held against rotation or, alternatively, the stems themselves may be rotated by gearboxes carried by the subframe, in which event gimbalmounted nuts at each extremity of the transverse members form th universal mounting for the vertical stems.

According to one embodiment ofthe invention bers, the position of the gearboxes during movement of the blade being defined by. their faced.

lugs or projections riding the beforementioned slide.

An appropriate construction of gearbox takes the form of a bracket or casing mounting a pair 1 of bevel wheels one carrying a nut on the screwthreaded stems and the other carried in bearings in th gearbox and connected to a flexible shaft for actuation. Each gearbox is trunnioned in a gimbal frame which is in turn trunnioned at the end of the transverse guides, the arrangements of the trunnions and gimbals being such as universally to mount the gearboxes through which pass the'vertical stems and which have outward projections with fiat faces engaging the guideways provided for the purpose in the structure and running parallel with the stems.

Th invention will be further described with reference to the accompanying explanatory drawings which illustrate by way of example one embodiment of blade grader and wherein:

Fig. 1 is a side elevation showing the longitudinal disposition of the control subframe mounting the plough circle, mouldboard and blade, and Figs. 2 and 3 are respectively a rear view and a front view of the blade mounting with the parts in their neutral or mid position.

Fig. 4 is a detail View of one of the trunnioned gearboxes to a larger scale and Fig. 5 is a longitudinal section of the central gearbox also to a larger scale.

Referring now to the drawings but first more particularly to Figs. 1-3, as in the grader described in the aforementioned Patent No. 2,074,081 a rigid front axle I is pivoted near the base of a central steering column 2, rotation of which for steering the grader to follow its tractor takes place about a king pin or vertical bearing 3. The column 2 depends from a U-shaped bearer 4 itself pivotal in a vertical plane about a transverse pin 5 borne in an inverted U-shaped bracket 6 which is welded to the bottom of the king pin or vertical bearing 3 and upon which bracket rests a rubbing plate I welded to the underside of the front end of the main frame constituted by longitudinal channel section girders 8.

The flexible mounting of the forecarriage relieves the grader frame of bending moment when traversing uneven surfaces, it being understood that the front axle is itself pivoted for limited angular vertical movement in relation to the steering column 2 about a cotter or pivot 9 whereby the front wheels readily accommodate themselves to transverse surface inequalities without subjecting the main frame of the grader to torsion.

.Also, as in my previous grader, a triangular drawbar assembly is provided for connecting the grader with its tractor or other towing vehicle, a'draw stirrup or eye |U being pivoted at the front end of a drawrod' H which is carried at thefront; apex of the triangular drawframe constituted by upper and lower girders I3 and I4 to which the drawrod transmits the tractive effort through a draft cushioning spring l2.

Mechanism is provided for steering the front wheels l5 from the platform 65 of the grader independently of the tractor as in my previous grader, whereby the operator may accurately steer the grader on the desired course in the wake of its tractor.

To this end the lower girder l4 of the drawbar assembly has a collar l8 at its rear end encircling a journal or bearing I9 projecting at the foot of (the steering column 2 and the upper arm I3 is furnished with a pair of eyes 20 which take 'lateral pins 2| on a double collar 22 encircling a second king pin 5 above and below a second collar 23 also encircling the king pin and which has a rearward projection mounting laterally projecting pins 24 similar to the pins 2| and constituting a horizontal bearing for a knuckle 25 through which draft stresses are transmittedto the plough circle generally designated 26 by draft arms 21 of an A frame.

When the steering mechanism is operated from the platform 65, the linkrods cause the drawbar to be offset from its normal position perpendicular to the front axle this movement being permitted by the collars l8 and 22 turning about the king pin l6 and aligned bearing l9 respectively.

The plough circle 26 with mouldboard 28 and blade 29 is slung from horizontal bearings 39 and 3| carried by an annulus or ring 32 encircling a subframe or rectangular control structure generally designated 33 and itself adjustable vertically and laterally in relation to the main frame 8 of the grader by the means now to be described.

Approximately midway of the main longitudinal frame 8 is an inclined seat 34 for a central gearbox 35 through which passes horizontally a lateral screwthreaded stem 36 anchored at its ends to arms or webs 64 bridging transverseguide members 31 and 38 disposed respectively in front of and behind the gearbox 35 and slidable laterally in relation to the seat 34 as the gearbox 35 is operated from the platform 65 of the grader to move the screwthreaded stem 36 to one side or another.

The transverse guide members 31, 38 mount near their extremities secondary gearboxes 39 and 40 through each of which passes an approximately vertical screwthreaded stem, 4| for the gearbox 39 and 42 for the gearbox 49, the ends of the stems 4| and 42 being anchored or fixed to the subframe or control structure 33. It will be noted by reference more particularly to Fig. 1 that the structure 33 and annular ring 32 in the neutral or mid position of the parts are inclined from the vertical, being perpendicular to the line constituting the axis of the virtual cone which has the ring 32 as its base and the draft pins 24 at its apex, the knuckle 25 being coincident with this axis which, as will be understood, shifts about its apex as the sub or control frame 33 is moved to adjust the depth of cut of the blade 29 and laterally as the subframe is sideshifted. Consequently for lateral movement of the subframe 33 and annulus 32 forming the base of the cone to effect .sideshift of the'blade'29. provision requires to be made for the central gearbox 35 to pivot about its seat 34 while bodily movement is prevented by the cap piece 43 and straps 44 which are bolted to the main frame member 8.

'To this end the gearbox 35; as shown in 'Fig. 5

is rotatably carried by cylindrical spigots I43, I34,

the former projecting downwardly from the cap piece 43 into the top of the gearbox'and the latter upwardly from the seat 34 into the bottom wall of the gearbox with their axes coincident and perpendicular to the seat 34 and in the plane of the cone base when the parts are in the neutral or mid position.

Thegearbox 35 is operated from the platform 65 by a handwheel 45 through the medium of telescopic shafting 46 and the gearboxes 39 and 40 are similarly operated fromthe platform by large handwheels 41 and 48. The gearboxes may include a bevel drive from the telescopic shafting to the nut member encircling the screwthreaded stem, 36 in the case of the gearbox 35, 4| in the case of the gearbox 39 and 42 in the case of the gearbox 48, although in the illustrated embodiment the central gearbox 35 includes a pair of helical gearwheels I49, I36, as shown in Fig. 5, the upper wheel I49 being mounted on a short shaft 49 coupled to the telescopic shafting 46 and the lower wheel I36 being threaded on the stem 36 and being borne in the gearbox 35 between thrust races I35. On the handwheel being rotated in one or other direction the second helical gearwheel or nut member I36 is correspondingly rotated and being held against lateral movement by its thrust races moves the screwthreaded stem 36 to one side or the other, in turn carrying the transverse guide members 31 and 38, the subframe 33, ring 32, and plough circle 26 to sideshift the blade 29.

To adjust the vertical position of the blade 29 the handwheels 41 and 48 are rotated to operate the gearboxes 39 and 49 and move their respective stems 4| and 42, while as aforementioned limited angular adjustment or cambering of the blade in the vertical direction can be effected through the medium of these gearboxes by setting one stem 4| in a different position to the other stem 42. To enable this to be effected the gearboxes 39 and 40 are not fixedly positioned at the extremities of the transverse guide members 31 and 3B but ride elongated slots 59 and 5| therein.

The gearbox 48 is illustrated in detail in Fig. 4 by reference to which it will be noted that a fabricated casing 52 has an upstanding bracket bearing 53 for an actuating bevel wheel 54 connected by the telescopic shafting aforementioned to the large handwheel 41, this actuating bevel being enmeshed with bevel teeth 55 formed at the upper extremity of a nut member 56 ridingthe screwed stem 42 and borne between thrust races 51 and 58 in the fabricated casing 52.

Projecting from each side wall of the casing 52 is a spigot or journal 59 riding in bearings provided for the purpose in a gimbal frame 6|], which in turn has spigots 01 journals 6| projecting forwardly and rearwardly into the elongated bearing slots furnished as aforementioned near the extremities of the front and rear lateral guide members 3! and 38, the arrangement being such that the gearbox 4|! may rockto the extent necessary to accommodate the angular setting of the subframe 33 for cambering the blade 29- about the journals-6| of itsgimbal frame, and also to a limited extent in the longitudinal plane-to allow for the variation in the inclination of the subframe 33 as the height of the blade 29 is adjustedon the casing journals 59 in the gimbal'frame 68.

Moreover the outside wall of the gimbal frame 691s formed witha flat rubbin'g'face 62 riding a i the left hand end trailing or vice versa.

vertical guide 63 which is formed for the purpose on the subframe 33 and which guide is parallel to the axis of the screwthreaded stem 42,

and irrespective of the adjusted position of the subframe 33 the guide face 62 of the gearbox gimbal frame 60 maintains contact with its guide 63 thereby stabilising the mounting of such subframe in any adjusted position and relieving the stems 4|, 42 of bending moment.

It will be understood that when the handwheels 41 and 48 are adjusted so that the screwstems 4| and 42 are symmetrically positioned in relation to the transverse guides 31 and 38 such as would normally be the case when the blade 29 is horizontal or is otherwise positioned by movement of the annular ring 32, the spigots 6| of both gearboxes 39 and 40 occupy the inner ends of their respective pairs of slots 59 in the transverse guide members 31 and 38 sothat the subframe 33 and with it the plough circle 26 and blade 29 are rigidly positioned in relation to the transverse guide members.

On the other hand, when theblade is cambered by adjusting the hand-wheels 41. and 48 to set the screw stems 4| and 42 asymmetrically thus to give the subframe 33 an angular setting, the pair of spigots 6| of either the gearbox 39 or the gearbox 49 will move outwardly along their respective slots 59 and under these circumstances the subframe 33 and with it the plough circle 26 and blade 29 is afforded limited lateral movement in relation to the transverse guide members 3'! and 38. Immediately the machine is put to work the blade reaction stabilises the mounting and removes any likelihood of chatter or apparent instability by urging the spigots 6| at one side of the subframe to the inner ends of their positioning slots 58. The particular side at which this abutment takes place is not dependent upon whether the blade is so cambered that the right or left hand end is lifted, but upon the angle of the blade to the direction of travel as adjusted by the plough circle 26, that is to say, whether the right hand end of the blade 29 is leading and Irrespective of which end of the blade 29 is lifted, the blade reaction when cutting and/or delivering soil causes the spigots 6| on the side of the machine containing the trailing edge of the blade to move to the inner ends of their slots andto remain there while the machine is at work with the blade so adjusted. Thus, if the plough circle is set with the right hand end of the blade 29 leading and the left hand end trailing, the spigots 6| of the left hand gearbox 39 will be urged to the inner ends of their locating slots 59 in the transverse guides 31 and 38 by the abutment between the left hand guide 63 on the subframe 33 and co-operating guide face 62 of the gearbox gimbal frame 69, whereby the thrust is directly transmitted from the subframe to the transverse guide members and the stems 4| and 42 are redinal girders and 8 constituting the main frame thus further to stabilize the mounting of the subframe 33.

The range of angular setting or cambering of the blade afforded by the screwed stems 4| and 42 is about 25 to each side of the horizontal and additionally the blade 29 may be moved to a position for backsloping or battering in which it may be inclined to an extent approaching- 80- on each side of the horizontal by relative movement of the ring 32 carrying the plough circle 26 aboutthe subframe 33.

To this end the ring 32 is borne onrollers l4, l5, 78, 11, carried adjacent the four corners of the rectangular subframe 33 and is furnished around its upper perimeter with internal teeth 18 with which enmeshes a pinion 19 carried in a gearbox 88 on the upper: cross member 8| of the sub-frame 33 and mechanically connected by telescopic shafting 82 to a handwheel 83, so that the operator on the platform 65 by rotating the handwheel 83 and thus the pinion 19 effects bodily rotation of the ring 32 riding on the rollers 'I41Tand takes with it the plough circle 26, mouldboard 28 and blade 29.

' At the lowerend of the subframe 33 a locking pin 84 is provided and ,co-operates with holes 85 in the annular ring 32 to fix the adjusted position ofthe latter, apedal 88 being provided on the platform 85 to release the pin 84 while the position of the ring 32 is being adjusted.

The subframe 33 is a built-up structure fabricatedfrom sheet metal and channel section frame members providing the vertical guides 63 and upper transom 8| carrying the gearbox 86 and lower transomcarrying the locking pin 84, these parts being bolted and/or welded together and carrying adjustable bearings for the rollers 14-41 upon which the ring 32 rides. The projecting corners of the subframe 33 locate such ring.

As in my prior construction all movements of the blade 29 originate from the common centre,

i. e., the centre of the ring 32 and subframe 33 which in the neutral position of the parts coincides with the middle of the lateral stem 36 passing through the central gearbox 35 on the longitudinal main frame of the grader and it is thus impossible for any two movements to confiict or jam.

Moreover, all movements of the blade are independently controllable from the platform without interaction, there being no loss of cut on sideshift or vice versa.

The common centre is itself movable in a rectangle limited only by the range of adjustment afforded by the lateral stem 36 and the vertical stems 4i and 42, and in addition to this bodily movement of the common centre or'rotational movement of the blade 29 and associated parts, e. g., for backsloping from a set position up to 80 at one side of'the machine to a similar position at the other can be had through the medium of the handwheel 83 and ring 32, while final adjustments in the set or camber of the blade and depth of cut can be accurately made on the vertical stems 4! and 42.

The plough circle 26 is equipped with conventional means enabling the blade incidence to be varied at will and the embodiment illustrated shows both front and rear axles furnished, with leaning wheel mecham'sm,- the rear axle 81 being also furnished with traversing means in the form of a nut 88 riding a screwed stem 89 operated by a handle 98 to enable the rear axle to be laterally shifted in relation to the main frame and platform of the grader, although as will be understood the means by which these ancillary movements are effected form no part of the present invention and indeed, where a simplified and cheapened machine is desired, may be omitted.

When moving the blade 28 to any required position only light pressure is necessary on the handwheels and to assist in the bodily upward movement'of the control subframe 33 carrying theQring' 32, plough circle 26, mouldboard 28 and blade 29 by means of the large handwheels 41, 48 operating the screwthreaded stems 4|, 42 through the gearboxes 39, 40, a pair of compression springs 66'working on guide rods 61 against an abutment 68 in the form of a webbed plate welded to and upstanding from the upper surface of the main frame 8 are connected over jockey-pulleys 69 by a flexible wire 13 to points on 'thefloWer part of the control subframe 33 adjacent the spaced hangers 30, 3| so as to exert an upward pull on the latter to counteract the weight jof'the plough circle and its associated parts. Thesprings 66 also function to stabilise themachine when in use. By'the present invention an improved construction of blade grading machine, patrol or maintainer is obtained, which is cheaply manufactured, more readily operated and durable in use;

What I claim is:

' '1. A blade mountingfor a grader and like vehicle ,havinga, longitudinally extending main frame, comprising a control subframe, means for moving said subframe vertically relative to said main frameincluding nut members borne by said main frame and screw stems fixedly positioned in said subframe and threaded through said nut members and guides on said subframe parallel to said stems'andengaging cooperating faces associated with said nut members.

2. Ablade mounting'according to claim 1 including a forecarriage wherein draft arms connect 'the lower part of the subframe with the forecarriage of the grader and the nuts are borne by lateral trunnions so as to be self-aligning with the stemsand so that their faces ride the guides on the subframe as the. longitudinal inclination of the latter changes consequent on vertical adjustment e 3. Ablade mounting for a grader and like vehicles having a longitudinally extending main frame,-comprising a control subframe carrying said blade, transverse guide members carried by the main frame means for moving said subframe vertically relative to said main frame including nuts "longitudinally trunnioned adjacent the extremities of; said guide members and stems fixedly--positioned i said subframe and threaded through said nuts, the trunnions being laterally movable in relation, to the guide members to permit lateral inclination of the subframe in relation to the main frame to camber the blade and members on-said frame having guides parallel to the stems and bearing on co-operating faces associated with the nuts.

- 4. A blademounting according to claim 3 including a 'forecarriage wherein draft arms connect the lower part of the subframe with the forec'a'rriag'e' of the grader and the nuts are borne by lateral trunnions in gimbal frames carrying thelongitudinal trunnions so as to be self-aligning with the stems and so that faces provided forthe purpose on the gimbal frames ride the guides, on the subframe as the longitudinal inclination. of the, latter changes consequent on vertical adjustment.

I 5. A; blademounting' according to claim 3 wherein the transverse guide members are slidable laterallyiin relation to'the main frame and have an'associated nut and transverse stem for effecting lateral adjustment between the subframe and the main frame to sideshift the blade. A blade;mounting according to claim 3 in--v eluding a forecarriage and draft arms, wherein a knuckle pin associated with the forecarriage pivotally mounts the draft arms to permit cambering of the blade, the knuckle pin being itself articulated to the forecarriage to permit vertical and lateral movement of the subframe and blade.

'7. A blade mounting according to claim 3 including transverse guide members wherein these are supported by rollers carried on arms projecting outwardly from the longitudinal main frame thus to stabilise the blade mounting.

8. A blade mounting according to claim 3 wherein the subframe carries rollers upon which rides an annular ring of angle or channel section in turn having brackets supporting the blade or the plough circle thereof.

9. A blade mounting according to claim 3 including a forecarriage and draft arms pivotally mounted on a knuckle pin articulated to the fore- I 12. A blade mounting according to claim 3 ineluding a spring means exerting an upward pull on the subframe to counteract the Weight of the parts and wherein such spring means operates through flexible wires anchored at widely spaced locations adjacent the foot of the subframe.

13. A blade mounting for graders according to claim 3 wherein the nuts are furnished with actuating gearing carried by gearboxes between thrust races in which the nuts rotate.

JOHN STEPHEN BURNS. 

